I find it interesting that you frame income inequality as "wealth polarisation." Are you implying a bimodal distribution of some sort?
My personal theory of "inequality" is that it isn't necessarily a bad thing. A distribution of income levels will always have a long right tail as you cannot make negative income but there is no theoretical limit to the maximum income. If all wages grow by the same relative amount, you would see increased inequality.
I think it is a problem if wages aren't growing for all portions of the distribution, but that is precisely because of the lack of growth for some and not because of the existence of growth for others. So, yes, I do think that growing income inequality may be a societal issue, but only if it is an effect of wage stagnation for middle and lower classes (which it is).
I do not believe that the rich getting richer is the cause of the stagnation, though. If anything, automation and globalization have been the main reasons for stagnation among middle and lower income levels. Automation and globalization may also be the cause of the continued growth in the very high wages. Even if they share the same underlying cause, one didn't cause the other.
I understand, but don't agree with, the argument that increased inequality causes social problems on its own. According to this theory, as I understand it, you can't have the differences among people be too great because it will cause too much power imbalance and resentment and eventually the masses will rise up and destroy the system from within. I don't agree, I think social problems come from the difference in reality compared to expectations of how one thought their future would go -- in other words, it is much worse for someone to see low wage growth in a stagnant economy where their standard of living is declining relative to their parents than it is to see moderate wage growth in a growing economy but there are some other people getting super, super rich. I don't think one's life relative to rich people is that important compared to one's life relative to personal expectations.
So, in that sense, I don't agree with redistribution schemes that intend on fixing a symptom of a problem (that rich people exist) rather than fixing a cause (wages are stagnant).
If the idea isn't to just reduce the inequality, but rather to supplement lower incomes -- there is absolutely no version of "taxing the mega rich" that we could do which would raise enough money to redistribute to the rest of workers such that it compensates them for the lack of wage growth at the lower end. It can't be done, there's not enough money. Eventually you have to tax the (productive) middle class.
From that perspective, I prefer policies that focus on wage growth for the lower and middle classes, even if that's a harder problem to solve.